Thin films of organic or polymeric materials with large second order optical nonlinearities in combination with silicon-based electronic circuitry have potential as systems for laser modulation and deflection, information control in optical circuitry, and the like.
Other novel processes occurring through third order nonlinearity such as degenerate four-wave mixing, whereby real-time processing of optical fields occurs, have potential utility in such diverse fields as optical communications and integrated circuit fabrication.
Of particular importance for conjugated organic systems is the fact that the origin of the nonlinear effects is the polarization of the .pi.-electron cloud as opposed to displacement or rearrangement of nuclear coordinates found in inorganic materials.
Nonlinear optical properties of organic and polymeric materials was the subject of a symposium sponsored by the ACS division of Polymer Chemistry at the 18th meeting of the American Chemical Society, September 1982. Papers presented at the meeting are published in ACS Symposium Series 233, American Chemical Society, Washington, D.C. 1983.
Of more specific interest with respect to the present invention embodiments is prior art relating to polymers with comb-like side chains. Eur. Polym. J., 18, 651 (1982) describes liquid crystalline polyvinyl polymers of the smectic and nematic types with cyanobiphenyl groups in the side chains.
The preparation of polyvinyl side chain polymers by free radical polymerization often is inhibited by the presence of structural substituents such as nitro groups. Polycondensation reactions are not inhibited in the manner of free radical reactions. SPIE-Int. Soc. Opt. Eng., 682 (Mol. Polym. Optoelectron. Mater: Funkam. Appl.) 65-69 (1987) by Griffin et al describes the production of side chain polyesters by a polycondensation reaction utilizing a titanium tetraisopropoxide catalyst. U.S. Pat. No. 2,631,992 describes the synthesis of linear polyamides from disubstituted malonic acid.
There is continuing interest in the theory and practice of polymers which are characterized by comb-like side chain structures which can be oriented in an applied external field.
There is also an increasing research effort to develop new nonlinear optical organic systems and devices adapted for laser frequency conversion, information control in optical circuitry, light valves and optical switches. The potential utility of organic materials with large second order and third order nonlinearities for very high frequency application contrasts with bandwidth limitations of conventional inorganic electrooptic materials.
Accordingly, it is an object of this invention to provide novel polymers with comb-like side chains.
It is another object of this invention to provide condensation polymers having side chains which exhibit nonlinear optical response.
It is another object of this invention to provide side chain polymalonamide polymers which exhibit nonlinear optical response, and which have superior film-forming properties.
It is a further object of this invention to provide optical light switch and light modulator devices with a transparent polymeric nonlinear optical component comprising a side chain polymalonamides.
Other objects and advantages of the present invention shall become apparent from the accompanying description and examples.